The present invention relates to water coolers and, more particularly, to a method of and an apparatus for cooling bottled water.
Bottled water is an attractive alternative to tap water and its use is widespread for many reasons. Bottled water dispensing units can dispense water at home, in the workplace, and in the marketplace for drinking, cooking, coffee, and other beverages without the need for a plumbed water supply. Bottled water supply units are often designed to occupy a minimum of floor or counter space. Recreational vehicle users and campers find bottled water to be a convenient water source while away from home or other plumbed water sources. Finally, bottled water often contains fewer contaminants and chemicals than ordinary tap water. The relative purity of bottled water makes it particularly useful in laboratory settings. However, the bottled water industry has long been challenged to find means for supplying water which has a temperature comparable to that of refrigerated water.
One existing conventional bottled water cooling systems and drinking water fountain cooling systems contains three fundamental parts which include an evaporator, a compressor, and a condenser. The evaporator or cold section allows pressurized refrigerant to expand, boil, and evaporate. During the change of state from a liquid to a gas, energy, in the form of heat, is absorbed. The compressor operates as a refrigerant pump and recompresses the gas into a liquid. The condenser expels the heat absorbed at the evaporator and the extra heat added by the compressor to the environment or ambient.
The refrigerants used in compression type refrigerated water dispensers have generated environmental concerns in that refrigerants are believed to be a factor in ozone layer deterioration, thereby making such systems unattractive from an environmental standpoint. Moreover, a compression refrigeration method such as this tends to have to be large in order to accommodate the three fundamental parts. Additionally, the pump action of the compressor creates intermittent, aggravating noise when it operates. Finally, maintenance problems result from the moving mechanical parts. Consequently, although many offices and workplaces enjoy the advantages and convenience of bottled water, a choice must often be made between a quiet atmosphere which necessitates room temperature water, and cold water which necessitates noise and maintenance. Also, compression refrigerated water coolers usually comprise a large stand-alone base or housing which requires much more space than a counter top bottled water dispensing system, which space may not be available in many settings.
One alternative that has been proposed to eliminate the problems of conventional refrigeration methods is to employ a thermoelectric cooling system, as disclosed in U.S. Pat. No. 3,008,299, issued to Sheckler on Nov. 14, 1961. The Sheckler reference discloses an adaptation of a thermoelectric cooling system to drinking water fountains of the bubbling type. In a thermoelectric cooling system, a cold junction exists where energy in the form of heat is absorbed by electrons as they pass from one semiconductor to another, thereby moving from a low energy state to a high energy state. A power supply provides the energy required to move the electrons through the system. A hot junction which is attached to a heat exchanger expels heat to the environment or ambient. While a thermoelectric cooling system for drinking water fountains which are hooked up to a plumbed water supply such as tap water is disclosed in the Sheckler reference, such a system has so far been unadaptable to bottled water units.
A characteristic of bottled water systems which has thus far prevented the adaptation of thermoelectric cooling supplies to existing bottled water systems is that they usually have a ceramic water receptacle. The difficulty has been in attaching a thermoelectric cooling system to a ceramic water receptacle in a manner which provides efficient cooling transfer. A further difficulty has been the difficulty of providing cooling means insertable within a previously defined area, which area is very limited.
One method that has been proposed in response to the size limitations is the utilization of a thermoelectric device wherein the heat sink is mounted externally. Such a device is disclosed in U.S. Pat. No. 3,310,953, issued to Rait on Mar. 28, 1967. However, important disadvantages of the Rait reference include inefficiency of cooling and excessive power consumption by the fan motor. Since the heat exchanger used in the Rait reference contacts only a portion of the bottom of the beverage container, there is inefficient transfer of heat from the beverage container to the external heat sink via the thermoelectric module. In addition, only a portion of the air moved by the fan moves through the fins of the heat exchanger, resulting in excessive power consumption by the fan motor. Finally, the external heat exchanger disclosed in Rait is excessively large and unduly expensive.
Another possible solution for providing cold liquids is disclosed in U.S. Pat. No. 3,250,433, issued to Christine et al on May 10, 1966. In the Christine et al reference, an entire liquid dispensing unit for dispensing cold liquids is constructed. However, the Christine et al reference is not proposed or adaptable for use with existing bottled water dispensing units. Hence, such a solution for cooling bottled water would be much more costly in that existing ceramic water receptacle units would have to be entirely replaced and users would be required to buy an entire new bottled water dispensing system in order to have cold water. Additionally, the design and configuration of the Christine et al reference precludes the use of a conventional bottle supplied by a bottled water supplier.
Consequently, it would be desirable to provide a bottled water supply cooling system which could cool bottled water to a temperature comparable to that of refrigerated water. It would also be desirable to provide a bottled water cooling system which would be adaptable for use with existing bottled water systems, including ceramic water receptacle systems. It would further be desirable to provide a bottled water cooling system which could operate from a standard 110 volt outlet and provide refrigeration without the use of refrigerants. Finally, it would be desirable to provide a bottled water cooling system utilizing an internal thermoelectric cooling system which would operate quietly and occupy a minimum of space.